While researching the book, I found hundreds of interesting facts! And I did try to get as many as possible into the book; I found it fascinating. Coming up with Henry’s lists for Cassie was an education in itself as I really had to try to get on the inside track with these cities when, in two of them –New York and Paris – I’m as much a tourist as the next guy.
For the New York section, I spent a lot of time reading up on the supposed whispering gallery in Grand Central station. I had the exact details of which pillar it was beside and even wrote a scene there, but in the end I took it out and decided not to use it, plumping for the one in St Paul’s in London instead. For the pacing of the plot, it made more sense for Cassie to whisper her secret in London, not New York!
For the scene where Cassie goes to the New York Library to read from the first edition of A Christmas carol, I did a ton of research not only into the rare portfolios they hold, but also the machinations of the Library itself. I was so fascinated to learn about the old vacuum shutes which literally had books whizzing through these huge pipes in protective capsules from one level to another. And this system worked not just in the library but along Brooklyn Bridge and under the pavements too.
For the Paris segment, I got really into researching the group cookery classes that are just so sought after and over-subscribed there. There’s such a scene for groups touring the markets – handling the produce, really examining the food they’re going to cook with and understanding that the success of their meals depends upon the quality of their ingredients. It’s got that great, St Germain student-vibe to it that we all buy into when we think of Paris – precious few people get to go to the Sorbonne, but a class teaching you to cook the perfect tarte tatin can give you the same Left Bank experience and I thought it was a good way to progress Cassie’s transition from country wife to street chick.
I also spent hours reading up on the catacombs for the Dior party scene. They run for hundreds of miles under the streets –imagine these tunnels literally made up of walls of bones and skulls! - and lots of people have gone in and never made it back out again. Genuinely scary.
It was difficult trying to get specific details on ‘flashmob’ street culture movements like the White Picnic although I got there in the end. Don’t tell anyone but it’s actually held in June, not April. (I had to jimmy the date for plot purposes.)
My favourite fact though, was the fact that a grown man can stand in the golden ‘ball’ spire at the top of the St Paul’s dome. I thought for a moment it had some ‘James Bond lair’ potential, but decided, on reflection that wouldn’t be quite appropriate! I just made them have a picnic breakfast there instead.